Organic light emitting diode with surface modification layer

A method of making a surface modification layer comprising the steps of:

• forming a first film having a first coefficient of expansion over at least a portion of a substrate, wherein the substrate comprises glass or a transparent polymeric material and wherein the first film comprises a nanoparticle;
• heating the substrate coated with the first film to an elevated temperature sufficient to cause the first film to expand to a second surface area;
• forming a second film over the first film having a second coefficient of expansion while the first film is expanded to have the second surface area;
• cooling the substrate coated with the first film and the second film thereby forming ridges and troughs in the second film,
• wherein the first coefficient of expansion is greater than the second coefficient of expansion;
• and
• forming an active stack over the second film.